Cyber Resilience

CVE-2021-29969

Medium

Published: 05 August 2021

Published
05 August 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0030 54.0th percentile
Risk Priority 12 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-29969 is a medium-severity Files or Directories Accessible to External Parties (CWE-552) vulnerability in Mozilla Thunderbird. Its CVSS base score is 5.9 (Medium).

Operationally, ranked in the top 46.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

If Thunderbird was configured to use STARTTLS for an IMAP connection, and an attacker injected IMAP server responses prior to the completion of the STARTTLS handshake, then Thunderbird didn't ignore the injected data. This could have resulted in Thunderbird showing…

more

incorrect information, for example the attacker could have tricked Thunderbird to show folders that didn't exist on the IMAP server. This vulnerability affects Thunderbird < 78.12.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

mozilla
thunderbird
≤ 78.12

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-552

Controls on authorized publication limit files and directories with nonpublic data from becoming accessible to external parties.

addresses: CWE-552

Controlling and documenting P2P file sharing prevents files and directories from being made accessible to external parties for unauthorized distribution.

addresses: CWE-552

Identifying and documenting file and directory locations allows restriction of access to external parties.

addresses: CWE-552

Protecting backup files ensures they are not accessible to external parties or unauthorized spheres.

addresses: CWE-552

Sanitizing equipment before off-site maintenance reduces the risk of files or directories containing sensitive data becoming accessible to external parties.

addresses: CWE-552

Policy restricts media access to authorized parties only, preventing exposure of resources to external or unauthorized actors.

addresses: CWE-552

Media access restrictions prevent files or directories from being accessible to external parties.

addresses: CWE-552

Employing and evaluating controls at documented alternate sites makes files and directories less likely to be accessible to external parties through physical or environmental weaknesses.

References